Date   

Re: Alternate pop fix...

ajparent1/KB1GMX <kb1gmx@...>
 

Skip,

M1/C51 or the top of the pot are the same effect for this.
The spot I picked allowed an easier dead bug hookup.

Allison


Re: The BITeensio board is here. #ubitx

Lawrence Macionski <am_fm_radio@...>
 

Jim-
Thank you for showing me the BITeensio Board at the swap-n-shop today!!..

Guys-
        I had the board in my hands and I have 40 years in IT/Heavy Military and NASA. It is Total 1st class quality.. Yes, I know there is a hundred ways to go to make your uBITX your's .. But seriously consider Jim's value added features and such to see if they are right for you.  Especially the 4 line display ability offers so much more than just 2.
Not that is is a negative but both Jim and I agree- Assembly requires patience, a very good soldering station, and soldering tools.. Plus if you are like us..You need  Geezer goggles!!!  (https://www.banggood.com/DANIU-White-10X-15X-20X-25X-Spectacles-Glasses-LED-Lamp-Magnifier-Loupe-Maintain-Tool-p-1067682.html?rmmds=detail-top-buytogether-auto__2&stayold=1&cur_warehouse=CN)

de Larry W8LM
ARRL Life Member - Licensed  368 DOG Years..


Re: Went Dead

Roy Appleton
 

Thank you very much for the information!

Roy
WA0YMH

On Sat, Jun 16, 2018, 1:21 PM Ralph Mowery <rmowery42@...> wrote:
This should be a link to my Google drive where you can see some pix.  With the RD16HHF1  if you lay the tab down on a table with the leads facing you , you have to cross the two leads on the right of both transistors so they will match the holes in the original ubitx .  You could use the original transistors but they would have to be insulated from the heat sink.  This ubitx has been modified in several ways and the output transformer was changed. 


I was lucky in that the box I found to put it in was just the size to cut a hole in the front for the display and in the back for the heat sink.  It was an old Bud box I picked up at a hamfest a while back that someone had started a project but never finished. 

I found the heat sink on ebay from China for about $ 5 shipped.  It was about 6 inches long, but I cut it to about 4 inches 


73 de ku4pt



On Sat, Jun 16, 2018 at 12:47 PM, Roy Appleton <twelveoclockhigh@...> wrote:
I'd love to see a close up of the new finals, crossed leads and heat sink if you could!

Roy
WA0YMH


Re: Alternate pop fix...

Skip Davis
 

Also move the parallel resistor/diode to the Raduino T/R and you won’t need the other diode you added.

Skip Davis, NC9O 

On Jun 16, 2018, at 18:06, Skip Davis via Groups.Io <skipnc9o@...> wrote:

Allison try moving the FET to the M1/C51 side and mute the audio preamp directly that is where I have it and I’m not experiencing any detectable pop in my headphones. Having said that, your results may very. 

Skip Davis, NC9O 

On Jun 16, 2018, at 16:28, ajparent1/KB1GMX <kb1gmx@...> wrote:

While working with the uBitx V3 I finally got annoyed enough by the pop to fix it.
Basically copied from uBITX V4 but it still popped some..

Parts count 4:
2 1n4148/914 diodes.
1 10K resistor (any value from 10 to 100K really)
1 2n7000 mosfet

Why the second diode?  The TX line is relay switched 12V and relays are not instant
they take milliseconds to physically move contacts.  So the second diode to the T/R line
form the Raduino its the fast acting audio kill as that the command to the relay.  The
second diode resistor is the hold until the relay returns to RX position.

TX muting with no pop, no thump.  

Allison

schematic enclosed.
<IMG_1834.JPG>


Re: Alternate pop fix...

Skip Davis
 

Allison try moving the FET to the M1/C51 side and mute the audio preamp directly that is where I have it and I’m not experiencing any detectable pop in my headphones. Having said that, your results may very. 

Skip Davis, NC9O 

On Jun 16, 2018, at 16:28, ajparent1/KB1GMX <kb1gmx@...> wrote:

While working with the uBitx V3 I finally got annoyed enough by the pop to fix it.
Basically copied from uBITX V4 but it still popped some..

Parts count 4:
2 1n4148/914 diodes.
1 10K resistor (any value from 10 to 100K really)
1 2n7000 mosfet

Why the second diode?  The TX line is relay switched 12V and relays are not instant
they take milliseconds to physically move contacts.  So the second diode to the T/R line
form the Raduino its the fast acting audio kill as that the command to the relay.  The
second diode resistor is the hold until the relay returns to RX position.

TX muting with no pop, no thump.  

Allison

schematic enclosed.
<IMG_1834.JPG>


Re: PA transistor uBITX

 

A friend of mine gave me a brand new static bag full of MTP3055V Mosfets, as it turns out they make 10 watts at 7mhz easily. Don't know about higher frequencies but it shows you just how many out there will work.

Joel
N6ALT


Re: Ubitx and Sherwood rx tests

ajparent1/KB1GMX <kb1gmx@...>
 

Sherwood only tests receivers so the only must have mod is the RX AGC ND6T flavor.

All the hot receivers are SDR and direct digital sample (flex, and Anan) thought the
7300 (also a SDR) is up there.

Of the radios using more conventional analog techniques two of mine the Atlas 
and the TT 340 are fair comparisons for single conversion.  The Tentec is the
only low IF with selectable filters at 9mhz to digital IF unlike those with VHF
first IFs.  Of those three the  listed radios Tentec Eagle, Atlas 215X,
Tentec 340/Triton  on the list in that order from best to worst.  This radio
without AGC is not likely to be above any of them.  Also the Atlas 215X a
1976ish design is a diode mixer front end like the uBitx with and AGC in
the IF and a diode mixer for product detector so it would compare
closest to the uBitx.  

Note: In dollars none of those radios even as used/broken approach 100$
and new were much more expensive by many times.

Comparable transceivers in the power class is FT817, IC703 and
Tentec Argonaut QRP series such as the used Argonaut model 505
that I use very regular for the 5W QRP level.

Reasons that is likely:
RX overload point, the limit here being the diode mixer. 
Filters First (45mhz) is wide and the second is fixed at SSB bandwidth.
close in and wide overload
Phase noise from the LO systems (LO1, LO2, BFO).

Sensitivity is never an issue.  

Allison


Re: Exciting times in the uBITx world

Joe
 

Lots of fun using the nextion displays and more users are jumping in by the day
Definitely my favourite display!

Using 3.2 Enhanced

Joe
Ve1bwv


On Sat, Jun 16, 2018, 3:22 PM William Cullison <wa8vih@...> wrote:
Just ordered my 2,8 display. I guess that leaves 5999 µBitx users left to order theirs. Not in a rush because this will be for my next µBitx. My first will be primarily used for barefoot digital and transverter  driver for 6 & 2.

73 Bill WA8VIH/4

On Sat, Jun 16, 2018 at 12:56 PM, Kees T <windy10605@...> wrote:
On Fri, Jun 15, 2018 at 09:01 pm, Mike Woods wrote:


Always good to see a nice crisp summary. 

It's just amazing what Ian Lee, KD8CEC, is able to do while keeping the original uBITX Raduino with the Nano microcontroller through extensive use of the microcontroller on the Nextion. Hats off to you Ian, you sure know what
you are doing.

73 Kees K5BCQ 



Alternate pop fix...

ajparent1/KB1GMX <kb1gmx@...>
 

While working with the uBitx V3 I finally got annoyed enough by the pop to fix it.
Basically copied from uBITX V4 but it still popped some..

Parts count 4:
2 1n4148/914 diodes.
1 10K resistor (any value from 10 to 100K really)
1 2n7000 mosfet

Why the second diode?  The TX line is relay switched 12V and relays are not instant
they take milliseconds to physically move contacts.  So the second diode to the T/R line
form the Raduino its the fast acting audio kill as that the command to the relay.  The
second diode resistor is the hold until the relay returns to RX position.

TX muting with no pop, no thump.  

Allison

schematic enclosed.


Re: Ubitx and Sherwood rx tests

iz oos
 

One without mods, the latest version. Btw most of the mods regard the TX, I have not seen so many mods at the RX.


Il 16/giu/2018 13:32, "Dennis Zabawa" <kg4rul@...> ha scritto:
Which variation?  Everyone builds theirs differently.


Re: Latest Build, Mods and results.

Paul k9mv
 

Mike-
Please specify what chokes you used to block feedback with the Adafruit mike.  I have a serious feedback problem using their P/N P1063 adjustable gain module.
Thanks.
-Paul  K9MV


Re: Went Dead

Ralph Mowery
 

The V4 board is the latest ubitx circuit board.  It has several modifications to it from the original ubitx circuit board.  One of the main ones is the audio IC was replaced by several transistors as there seems to be a real quality control problem with the original IC.  

Mr. Farhan is looking at all the mods that have been made by others and using some of the best of them in the V4 boards.

While the original works very well for the price there have been lots of modifications to it and the software.  I think he did a great job of making the original by keeping the price very low.  While I can not do much with the engineering of the electronics, I have enjoyed making some of the modifications to the ubitx.  I look at this as the way I am at chess.  I know how each piece moves, but when playing with a real chess player I get beat in about 3 moves because I don't know how to hook it all together.

The IRF510 can be mounted by using the insulators.  I don't know much about the IRF510 but the RD16HHF is a 'real' RF device and the specs say it will withstand a SWR of about 20 :1 .  However it is about $ 10 per pair instead of the $ 1 a pair for the IRDF510s.

de ku4pt


On Sat, Jun 16, 2018 at 3:09 PM, Bill Watkins <kf7yxs@...> wrote:
What’s a V4 board, and since I’ve already ordered the 510,  that will be what I have for awhile.  


On Jun 16, 2018, at 14:00, ajparent1/KB1GMX <kb1gmx@...> wrote:

The V4 board solves the crossover problem.  

The RD16HHF is a device people have used and its a good part but its also 10$ for a pair 
from reputable sources.  Apply the mods suggested by the users of that part for best result.

As to mounting the original IRF510 there are insulator kits and silicon based heat transfer
grease that its the time tested solution.

Allison
_


Re: Went Dead

ajparent1/KB1GMX <kb1gmx@...>
 

The QCX is a very different beast from the uBitx.

The QCX uses a class E final the expects the transistor to act very much like a switch.
The advantage is extremely high efficiency over 85% its typical or higher and very
little power expended in the device. The need is the device must switch fast and hard
and IRF510 and RD parts while they can do this need much more energy into the
gate to do it.  The reward is if done well a single IRF510 will do 30-40W at 12V, however
its not a drop in thing.  These are typically monoband designs.  This works well for
CW, AM, and other constant carrier modes.

The uBitx uses a series of linear amp stages that include the finals.  At best efficiency of
each stage may be 55% or lower with a fair amount of power and heat expended.
This is a requirement for undistorted SSB and multiband designs.

What applies to QCX and uBitx are very different.

Allison


Re: Went Dead

Bill Watkins
 

What’s a V4 board, and since I’ve already ordered the 510,  that will be what I have for awhile.  


On Jun 16, 2018, at 14:00, ajparent1/KB1GMX <kb1gmx@...> wrote:

The V4 board solves the crossover problem.  

The RD16HHF is a device people have used and its a good part but its also 10$ for a pair 
from reputable sources.  Apply the mods suggested by the users of that part for best result.

As to mounting the original IRF510 there are insulator kits and silicon based heat transfer
grease that its the time tested solution.

Allison


Re: Went Dead

ajparent1/KB1GMX <kb1gmx@...>
 

The V4 board solves the crossover problem.  

The RD16HHF is a device people have used and its a good part but its also 10$ for a pair 
from reputable sources.  Apply the mods suggested by the users of that part for best result.

As to mounting the original IRF510 there are insulator kits and silicon based heat transfer
grease that its the time tested solution.

Allison


Re: PA transistor uBITX

ajparent1/KB1GMX <kb1gmx@...>
 

THat part is fairly close to the IRF530 and would work ok for the lower bands.

Input capacitance 350pf, robust current at 16A peak, still power limited due to
the device package to 25W.

I've tried the P16NF06 and it was high input capacitance, it was fine for 160 through 40
but getting it to go at 10M required a vastly different circuit due to the low input impedance.

There are a slew of nearly the same parts in the same case characterized as switches but
few that have been tested for linear amplification and then only by hobby users.  Its the
price paid for cheap.  

I can suggest a list many I've not tried.  But my preference leans to LDMOS and other RF
characterized devices.   Many are not cheap like IRF510 but they tend to be very durable.
Then again in the 5 to 55$ range you get what you paid for (least from reliable sources).

Allison


Re: Went Dead

Bill Watkins
 

Very interesting and clever.  Thanks for the tip.  How closely are the RD16HHF1 equivalent to the original mosfet?  I do like being able to bolt the heat sink to the case and use the case which is already ground to handle some heat and secure things.  Like you say, not a possibility with the original mosfet.


Bill



On Jun 16, 2018, at 11:21 AM, Ralph Mowery <rmowery42@...> wrote:

This should be a link to my Google drive where you can see some pix.  With the RD16HHF1  if you lay the tab down on a table with the leads facing you , you have to cross the two leads on the right of both transistors so they will match the holes in the original ubitx .  You could use the original transistors but they would have to be insulated from the heat sink.  This ubitx has been modified in several ways and the output transformer was changed. 


I was lucky in that the box I found to put it in was just the size to cut a hole in the front for the display and in the back for the heat sink.  It was an old Bud box I picked up at a hamfest a while back that someone had started a project but never finished. 

I found the heat sink on ebay from China for about $ 5 shipped.  It was about 6 inches long, but I cut it to about 4 inches 


73 de ku4pt



On Sat, Jun 16, 2018 at 12:47 PM, Roy Appleton <twelveoclockhigh@...> wrote:
I'd love to see a close up of the new finals, crossed leads and heat sink if you could!

Roy
WA0YMH



Re: Exciting times in the uBITx world

William Cullison
 

Just ordered my 2,8 display. I guess that leaves 5999 µBitx users left to order theirs. Not in a rush because this will be for my next µBitx. My first will be primarily used for barefoot digital and transverter  driver for 6 & 2.

73 Bill WA8VIH/4

On Sat, Jun 16, 2018 at 12:56 PM, Kees T <windy10605@...> wrote:
On Fri, Jun 15, 2018 at 09:01 pm, Mike Woods wrote:


Always good to see a nice crisp summary. 

It's just amazing what Ian Lee, KD8CEC, is able to do while keeping the original uBITX Raduino with the Nano microcontroller through extensive use of the microcontroller on the Nextion. Hats off to you Ian, you sure know what
you are doing.

73 Kees K5BCQ 



Re: Went Dead

Ralph Mowery
 

This should be a link to my Google drive where you can see some pix.  With the RD16HHF1  if you lay the tab down on a table with the leads facing you , you have to cross the two leads on the right of both transistors so they will match the holes in the original ubitx .  You could use the original transistors but they would have to be insulated from the heat sink.  This ubitx has been modified in several ways and the output transformer was changed. 


I was lucky in that the box I found to put it in was just the size to cut a hole in the front for the display and in the back for the heat sink.  It was an old Bud box I picked up at a hamfest a while back that someone had started a project but never finished. 

I found the heat sink on ebay from China for about $ 5 shipped.  It was about 6 inches long, but I cut it to about 4 inches 


73 de ku4pt



On Sat, Jun 16, 2018 at 12:47 PM, Roy Appleton <twelveoclockhigh@...> wrote:
I'd love to see a close up of the new finals, crossed leads and heat sink if you could!

Roy
WA0YMH


Re: TX Debug Steps?

Bill Cromwell
 

Hi,

Don't use the light bulb to sort things. If you don't have the gear or the knowhow you might find somebody at a local radio club who can help you. I haven't read all of your posts but maybe the problem is not your radio at all. For instance..do you already know that your antenna system works? As in..it has made QSOs for you with a different radio?

73,

Bill KU8H

On 06/16/2018 01:27 PM, W8SWG wrote:
Well thanks for everyone's help but it is apparent that I do not have
the technical expertise to debug this radio. I have given every bit of
the patience I can muster. I will have to try to find someone to repair
it for me before I kick it across the room.
_._,_._,_
--
bark less - wag more